1. Field
The present disclosure relates to a system and a method for providing navigation instructions, and more particularly to a system and a method for providing navigation instructions at optimal times.
2. Description of the Related Art
Navigation systems have been in use for years and are capable of providing navigation instructions to a user based on a current location and a desired destination. Typically, these navigation systems are used in cars for providing driving directions. These navigation systems utilize Global Positioning System (GPS) technology for estimating the current location of the car. GPS technology may, according to the United States Government, have an accuracy of a 7.8 meters variance with a 95% confidence level. High quality GPS technology may have a variance that is within 3.5 meters. This accuracy is typically sufficient for a vehicle as roads are typically at least a few meters wide and cars move at a rate that reduces the impact of a 3.5 meter variance.
These navigation systems may provide turning instructions as a driver approaches a turn. They may output the instructions a predetermined distance prior to a turn so that the driver can be notified of the turn prior to approaching the turn. Even considering the variance of the GPS technology, these instructions are typically provided with adequate time for the driver to prepare for and take the turn. This is because even if the GPS locates the vehicle 7.8 meters closer to the turn, the instruction will be provided to the user with sufficient time because 7.8 meters is negligible at most vehicle speeds.
More recently, portable navigation systems have been developed. For example, many smartphones and other mobile devices currently include navigation systems. Users can now use these portable navigation systems when riding a bike, walking or otherwise proceeding along a route at a slow speed relative to a car. These portable navigation systems, as the vehicle-based navigation systems, use GPS technology for estimating a current location of the navigation system. This technology is usually, but not always, adequate for this type of use as the navigation system can minimize the risk of a user missing a turn. This is because the navigation systems can output the instruction at a sufficiently large distance prior to the turn so that the user can look for the turn as he/she approaches the turn.
However, individuals having certain disabilities, such as blindness, cannot detect turns as they approach. In order for these individuals to gain the most benefit from a navigation system, the navigation system should output the instruction at an optimal time so that the user knows the exact moment for turning. A difference of even 3 meters can make a large impact on a disabled user's use of a navigation system. Therefore, navigation systems using solely GPS technology may not be usable or optimal for disabled users.
Thus, there is a need for systems and methods for providing navigation instructions to users at precise times.